Mehajer phone allegedly had 'forged' email

Detective Sergeant Matt Taylor claims he was investigating allegations Mehajer staged a car crash to avoid a court hearing when he discovered an image of the email earlier this year.

It was on a phone seized from Mehajer's Lidcombe home in late 2017, the court heard on Tuesday.

The email related to a court case involving the tax office and the Mehajer Brothers company and an image of it was sent to a third party, the police officer said in a letter read at Mehajer's NSW Supreme Court bail hearing.

The email image is under investigation and the 32-year-old hasn't been charged.

Salim Mehajer arrives at Central Local Court, Sydney on June 14 (AAP)

"I still maintain my innocence for that," Mehajer told the court on Tuesday.

Det Sgt Taylor in his letter to the court said the contents of the email were false and it used an outdated signature which featured in an unrelated 2016 email he sent Mehajer.

It begins with "Hi Salim" and allegedly says: "We are not inspecting the collision. The accident was given the all-clear by the NRMA."

"Considering you have a perfect tract (sic) record with Mercedes Australia service, there should not be a long turnaround time in returning your vehicle," it also states.

Mehajer was in January 2018 charged over an allegedly staged 2017 crash which saw his Mercedes AMG collide with another vehicle just before he was meant to appear in court over a taxi driver assault.

He was charged with perverting the course of justice and conspiring to cheat and defraud an insurer.

Mehajer is fighting the allegations and on Tuesday asked why he would stage a crash to avoid court when he wouldn't get a jail sentence over the assault.

The former Auburn deputy mayor was unsuccessfully applying for bail pending a NSW District Court appeal of his conviction and sentence over electoral fraud offences.

He was jailed in June for 21 months, to be released after 11 months, after a magistrate found him guilty of 77 charges related to a joint criminal enterprise with his sister aimed at influencing the 2012 Auburn council vote.

Mehajer during Tuesday's hearing argued he needed bail to prepare for his appeal, saying "the only thing I want is a fair trial".

But Justice Robert Allan Hulme said there was a significant prospect of him committing serious offences if released.

"Mr Mehajer has an arrogant disregard for the law of this state and there is a very significant prospect that if granted bail he will breach it," he said.

"He will blame others for the breach and deflect responsibility from himself."